Minimal pulsation ophthalmic probe

ABSTRACT

An ophthalmic apparatus for performing an ocular surgery may include an ophthalmic probe body having an inner cutting member at least partially disposed within and moveable relative to an aspiration tube within the probe body to facilitate flow of aspiration fluid. A motor within the body may be configured to actuate the inner cutting member relative to the aspiration tube.

CROSS-REFERENCE TO RELATED APPLICATION

The present disclosure is a continuation of U.S. patent application Ser.No. 14/244,986, entitled “Minimal Pulsation Ophthalmic Probe,” filedApr. 4, 2014, the entire disclosure of which is hereby incorporated byreference.

FIELD OF THE INVENTION

The present disclosure pertains to ophthalmic probes, systems, andmethods. More particularly, but not by way of limitation, the presentinvention pertains to ophthalmic probes, systems, and methods utilizingan aspiration arrangement that may reduce the impact of fluidpulsations.

BACKGROUND

Microsurgical procedures frequently require precision cutting and/orremoving various body tissues. For example, certain ophthalmic surgicalprocedures require cutting and removing portions of the vitreous humor,a transparent jelly-like material that fills the posterior segment ofthe eye. The vitreous humor, or vitreous, is composed of numerousmicroscopic fibrils that are often attached to the retina. Therefore,cutting and removing the vitreous must be done with great care to avoidtraction on the retina, the separation of the retina from the choroid, aretinal tear, or, in the worst case, cutting and removal of the retinaitself. In particular, delicate operations such as mobile tissuemanagement (e.g. cutting and removal of vitreous near a detached portionof the retina or a retinal tear), vitreous base dissection, and cuttingand removal of membranes are particularly difficult.

The use of microsurgical cutting probes in posterior segment ophthalmicsurgery is well known. These cutting probes typically include a hollowouter cutting member (the needle), a hollow inner cutting member (thecutter) arranged coaxially with and movably disposed within the hollowouter cutting member, and a port extending radially through the outercutting member near the distal end thereof. Vitreous humor and/ormembranes are aspirated into the open port, and the inner member isactuated, closing the port. Upon the closing of the port, cuttingsurfaces on both the inner and outer cutting members cooperate to cutthe vitreous and/or membranes, and the cut tissue is then aspirated awaythrough the inner cutting member.

The inner cutting member (or cutter) in conventional vitrectomy cuttingprobe systems typically connects with a larger tube within the probe viaa coupling device. With each cutting cycle, the inner cutting member (orcutter), the coupling device, and the larger tube all axially displaceby an amount equal to the cutting stroke length, thereby cutting thevitreous that entered the port. However, the cutting motion also resultsin a change of the internal fluid volume of the ophthalmic probe. Thisis due to the difference in internal cross-sectional area between thecutter and the larger tube in conjunction with the axial motion of thistransition. The volume change may cause pressure pulses and fluidagitation which could result in fluid pumping, and due to the vacuumpresent, could drive some gas out of solution, thereby producingbubbles. Further, while most of the excess volume may propagate up theaspiration tube, some of the volume may manifest itself as pulses oreven a reversal of flow during vitrectomy cutting. It may also createsome agitation that results in gas coming out of solution.

The present disclosure is directed to addressing one or more of thedeficiencies in the prior art.

SUMMARY

In some exemplary aspects, the present disclosure is directed to anophthalmic apparatus for performing an ocular surgery. The apparatus mayinclude an ophthalmic probe body graspable by a user and a cutterextending from the body and comprising an inner cutting member and aneedle. The inner cutting member may be at least partially disposedwithin and moveable relative to the needle, and the inner cutting membermay have a lumen having a first diameter. The needle may have a distalend with a port formed therein for receiving patient tissue. Anaspiration tube within the probe body may be disposed to extend from theend of the inner cutting member to an aspiration line from the probebody, the aspiration tube having a second diameter greater than thefirst diameter to facilitate flow of aspiration fluid. A motor withinthe body may be configured to actuate the inner cutting member relativeto the needle and relative to the aspiration tube.

In an aspect, the inner cutting member is coaxial with the aspirationtube. In an aspect, the aspiration tube is fixed in place so as to bestationary relative to the probe body. In an aspect, the ophthalmicapparatus includes a drive shaft connected to the motor and a couplercoupling the drive shaft to the inner cutting member so that when themotor actuates the drive shaft, the coupler actuates the inner cuttingmember. In an aspect, the drive shaft is larger than the aspirationtube, the aspiration tube being disposed within the drive shaft. In anaspect, the drive shaft is coaxial with the aspiration tube. In anaspect, the aspiration tube extends through a central portion of themotor. In an aspect, the ophthalmic apparatus includes a cutter sealassembly affixed to the aspiration tube, the cutter seal assemblycomprising a seal that prevents the passage of fluid. In an aspect, themotor is affixed directly to the inner cutting member.

In some exemplary aspects, the present disclosure is directed to anophthalmic apparatus for performing an ocular surgery and includes anophthalmic probe body graspable by a user and a cutter extending fromthe body and comprising an inner cutting member and a needle. The innercutting member may be at least partially disposed within and moveablerelative to the needle. The inner cutting member may have a lumen havinga first diameter, the needle having a distal end with a port formedtherein for receiving patient tissue. An aspiration tube may be fixed inplace relative to the probe body and may extend from the end of theinner cutting member to an aspiration line from the probe body. Theaspiration tube may have a second diameter greater than the firstdiameter to facilitate flow of aspiration fluid. A motor may be disposedwithin the body and may be coupled to the inner cutting member. Themotor may be configured to actuate the inner cutting member relative tothe needle.

In an aspect, the inner cutting member is coaxial with the aspirationtube. In an aspect, the motor is configured to actuate the inner cuttingmember relative to the aspiration tube. In an aspect, the ophthalmicapparatus includes a drive shaft connected to the motor and a couplercoupling the drive shaft to the inner cutting member so that when themotor actuates the drive shaft, the coupler actuates the inner cuttingmember. In an aspect, the drive shaft is larger than the aspirationtube, the aspiration tube being disposed within the drive shaft. In anaspect, the drive shaft is coaxial with the aspiration tube. In anaspect, the aspiration tube extends through a central portion of themotor. In an aspect, the ophthalmic apparatus includes a cutter sealassembly affixed to the aspiration tube, the cutter seal assemblycomprising a seal that prevents the passage of fluid. In an aspect, theaspiration tube comprises a portion of an aspiration pathway in theprobe body, and only the inner cutting member displaces within theaspiration in a manner impacting the volume of the aspiration pathway.In an aspect, the motor is affixed directly to the inner cutting member.

In some exemplary aspects, the present disclosure is directed to methodsof driving an inner cutting member of an ophthalmic probe. The methodsmay include opening an aspiration port in a needle of a distallyprotruding cutter by driving a motor to drive an inner cutting member ina proximal direction. The aspiration port, the inner cutting member, andan aspiration tube may form a portion of an aspiration pathway throughthe ophthalmic probe. The inner cutting member may have a first diameterand the aspiration tube may have a second diameter greater than thefirst diameter. Driving the inner cutting member in the proximaldirection may include moving the inner cutting member relative to theaspiration tube. The method may also include closing the aspiration portto cut tissue in the aspiration port by driving the motor in theophthalmic probe to drive the inner cutting member in the distaldirection relative to the needle and displacing the inner cutting memberrelative to the aspiration tube.

In an aspect, the aspiration tube is fixed in place within theophthalmic probe and the volume of the aspiration pathway in theophthalmic probe changes only by the volume equal to the axialdisplacement of the inner cutting member. In an aspect, driving a motorto drive an inner cutting member includes driving a drive shaftconnected to the motor, and driving a coupler connected to the driveshaft, the coupler being connected to the inner cutting member at alocation distal of the aspiration tube.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory innature and are intended to provide an understanding of the presentdisclosure without limiting the scope of the present disclosure. In thatregard, additional aspects, features, and advantages of the presentdisclosure will be apparent to one skilled in the art from the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate embodiments of the devices andmethods disclosed herein and together with the description, serve toexplain the principles of the present disclosure.

FIG. 1 is an illustration of an exemplary ophthalmic surgical systemaccording to one aspect of the present disclosure implementing theprinciples and methods described herein.

FIG. 2 is a cross-sectional diagram illustrating an ophthalmic probe ofthe exemplary ophthalmic surgical system of FIG. 1 according to anaspect of the disclosure.

FIG. 3 is a cross-sectional diagram illustrating a distal end of acutter of the exemplary ophthalmic probe of FIG. 2 according to anaspect of the disclosure.

FIG. 4 is a detailed view of a portion of the ophthalmic probe of FIG. 2according to an aspect of the disclosure.

FIG. 5 is a cross-sectional diagram illustrating another ophthalmicprobe of the exemplary ophthalmic surgical system of FIG. 1 according toan aspect of the disclosure.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the disclosure is intended. Any alterations and furthermodifications to the described devices, instruments, methods, and anyfurther application of the principles of the present disclosure arefully contemplated as would normally occur to one skilled in the art towhich the disclosure relates. In particular, it is fully contemplatedthat the features, components, and/or steps described with respect toone embodiment may be combined with the features, components, and/orsteps described with respect to other embodiments of the presentdisclosure. For simplicity, in some instances the same reference numbersare used throughout the drawings to refer to the same or like parts.

The present disclosure is directed to surgical devices, systems, andmethods for performing ophthalmic surgeries. The surgical devicesinclude, for example, an ophthalmic probe having reduced pulsing andfluid agitation than prior devices. It does this by minimizing the fluidvolume displacement during a cutting cycle. That is, in some embodimentsof the present disclosure, the ophthalmic probes include a hollow needleconnected with a larger tube by a coupling device that does notoscillate with the hollow needle and with the larger tube. Because ofthis, the fluid volume within the ophthalmic probe is maintained asrelatively constant. This relatively constant fluid volume, therefore,more fully reduces a chance of fluid surge or fluid agitation that mayresult in undesirable fluid resistance or back flow. This also mayresult in a smoother, more consistent flow, providing predictability andaccuracy for an operating surgeon. In turn, this may result in a betterpatient outcome.

FIG. 1 illustrates an ophthalmic surgical system, generally designated10, according to an exemplary embodiment. The surgical system 10includes a base housing 12 and an associated display screen 14 showingdata relating to system operation and performance during an ophthalmicsurgical procedure. The surgical system 10 includes an ophthalmic probe100 structurally configured in a manner that reduces or minimizes fluidsurges during the surgical procedure. In some embodiments, theophthalmic surgical system 10 is a vitrectomy surgical system used toperform vitrectomy procedures to remove vitreous humor or other tissuefrom the eye.

In some embodiments, the surgical system 10 includes a fluidic pressuresource and a probe driver disposed in or forming a part of the basehousing 12. In some exemplary embodiments, the fluidic pressure sourceis a high pressure tank and compressor that provides driving fluidicpower to drive the ophthalmic probe 100. Some exemplary pressure sourcesare pneumatic pressure sources arranged to provide compressed air todrive the ophthalmic probe 100. In some embodiments, the pneumaticpressure source is contained on or in the base housing 12, while inother embodiments, the pressure source is disposed elsewhere in or aboutthe operating room.

The probe driver may be a pressure pulse generator, such as one or morestandard three-way or four-way valves, for example. Some embodimentsemploy a solenoid that displaces a spool between a charge and adischarge position. The probe driver, sometimes referred to as apressure pulse generator, cycles to set the cutting rate of theophthalmic probe 100.

The ophthalmic probe 100 and the base housing 12 are in fluidcommunication with each other along lines 16 representing flow paths orflow lines. Depending on the embodiment, the lines may include a supplyline and an aspiration line between the base housing 102 and theophthalmic probe 100. The supply line may have a lumen that carries aconstant or pulsating pressurized fluid for driving an actuator or motorin the ophthalmic probe 100. The aspiration line also extends from thebase housing 102 to the ophthalmic probe 100 and is used to aspiratefluid and tissue from the probe 100.

FIG. 2 illustrates a cross-sectional view of an ophthalmic probe 100according to an exemplary embodiment of the present disclosure forremoving fluid/tissue from a patient's eye. In some aspects, theophthalmic probe 100 is an ophthalmic probe usable in vitrectomyprocedures. During such procedures, the probe may be used to penetratethe eye globe to access the vitreous humor or other tissue containedtherein. The ophthalmic probe 100 may cut the vitreous humor or othertissue and aspirate it to the base housing 12 of the ophthalmic surgicalsystem 10. It may find particular utility for removing intraoculartissue during an ophthalmic procedure to re-attach a retina of an eye.Although use in an ophthalmic procedure is described, it is to beunderstood that the ophthalmic probe 100 can be used to cut and aspirateother tissue, such as polyps, fibroids, and other human tissue.

The ophthalmic probe 100 includes a housing 102, a motor 104 disposedwithin the housing 102, a cutter 105 extending from the housing 102, anda cutter assembly 108.

The housing 102 includes a handle portion 110 and a motor portion 112.The handle portion 110 includes a handle body 114. The handle body 114extends in a proximal direction from a distal end 120 toward the motorportion 112. An over-molded grip 122 extends about the handle body 114.The grip 122 may be contoured for comfortable grasping by a user.

The motor portion 112 is disposed proximal of the handle portion 110,and includes a rear motor housing 124 and a front motor housing 126. Therear motor housing 124 includes communication ports 128, 130 thatprovide communication between the ophthalmic probe 100 and the surgicalsystem 10. It also includes an aspiration port 131 that providescommunication between an aspiration pump at the surgical system 10 andthe probe 100. In this embodiment, the communication ports 128, 130 arepneumatic ports, and the motor portion 112 is configured to hold afluidically driven motor, such as, for example, a pneumatically drivenmotor. It's worth noting that other embodiments include alternativeprobe motors. For example, some embodiments include a fluidically drivenpiston motor in place of a diaphragm.

The ports 128, 130, 131 extend from the proximal end of the rear motorhousing 124 toward the distal end of the rear motor housing 124. Thefront motor housing 126 is disposed distal of the rear motor housing 124and is arranged to interface with the handle portion 110. The rear motorhousing 124 is configured to provide communication to the surgicalsystem 10, and the front motor housing 126 cooperates with the rearmotor housing 124 to securely support the motor 104 of the ophthalmicprobe 100.

In this embodiment, the rear motor housing 124 and the front motorhousing 126 are shaped to cooperatively form a motor chamber 134. Inthis embodiment, the chamber 134 is a transversely extending hollowconfigured to hold the motor 104 for driving the cutter assembly 108.The rear motor housing 124 and front motor housing 126 include passages136, 138 that respectively extend between the rear motor housingcommunication ports 128, 130 and the motor chamber 134. In theembodiment of FIG. 2, the ports 128, 130 are in fluid communication withopposing sides of the motor chamber 134, and here, are in communicationwith the distal and the proximal portions of the motor chamber 134. Assuch, the ports 128, 130 are in fluid communication with opposing sidesof the motor 104.

The motor 104 is disposed within the motor chamber 134 and is configuredto drive the cutter assembly 108. In this way, the cutter assembly 108can be used to cut and aspirate tissue, such as intraocular or othertissue. The motor 104, in this embodiment is a pneumatically drivenmotor, formed of a flexible diaphragm 140 and a rigid coupler 142. Itoperates by pressure variation between the first and second ports 128,130 and thus, on opposing sides of the motor 104. The variation inpressure on opposing sides of the motor 104 within the motor chamber 134causes the diaphragm 140 to vibrate, carrying portions of the cutterassembly 108 in a back-and-forth oscillating motion.

The distal end of the pneumatic probe 100 includes the cutter 105. Thecutter 105 includes a needle 106 and an inner cutting member 149. Theneedle 106 is a hollow cylinder and extends from the housing 102. Itincludes a closed end and an outer port that receives tissue, such asophthalmic tissue, and it cooperates with the cutter assembly 108.

A distal end of the cutter 105 is shown in FIG. 3. The needle 106includes a closed end 144 and an outer port 146 that receives tissue,such as ophthalmic tissue. The outer port 146 is in fluid communicationwith an inner channel 148. The inner cutting member 149 is locatedwithin the inner channel 148 of the needle 106. The inner cutting member149 has an inner bore 150, an open end 152, and a cutting surface 154.As will be described below, the inner bore 150 is in fluid communicationwith the aspiration line of the ophthalmic probe 100. The aspirationline connects to a vacuum pressure that pulls tissue into the outer port146 when the inner cutting member 149 is located away from the port 146.The inner cutting member 149 moves within the inner channel 148 of theneedle 106 to cut tissue that is pulled into the outer port 146 by theaspiration system. The ophthalmic tissue received by the outer port 146is preferably vitreous or membranes.

It is worth noting that other embodiments have a distal end of thecutter 105 where a distal end of the inner cutting member 149 includes aport extending radially therethrough. As the edges of the radial port ofthe inner cutting member 149 pass the edges of the outer port 146 of theouter cutting member, the cutting may take place both on the distalstroke and on the proximal stroke, making a dual cutting cutter. Oneexample of such an embodiment is shown in U.S. Pat. No. 5,106,364,incorporated herein by reference. Other arrangements are alsocontemplated.

Returning to FIG. 2, the cutter assembly 108 includes a drive shaft 156,a coupler 158, a stationary aspiration tube 160, a cutter seal assembly162, and the inner cutting member 149. As shown in FIG. 2, the driveshaft 156 connects to and extends from the motor 104 and extendssubstantially centrally through the body portion 110 toward the distalend of the ophthalmic probe 100. The drive shaft 156 is a relativelylarger diameter tube structurally configured to transmit loading appliedby the motor 104 to the coupler 158 and ultimately to the inner cuttingmember 149. In this embodiment, the drive shaft 156 is a cylindricaltube, but other shapes are contemplated. For example, the drive shaft156 may be a square, a triangle, or other shape having a central passageor opening. As will be described further below, the aspiration tube 160and the cutter seal assembly 162 are disposed within the lumen or tubeof the drive shaft 156. In some embodiments, to reduce mass, the driveshaft 156 is configured of a plurality of longitudinally extendingstruts or supports, spaced apart by windows or gaps in the drive shaftsidewall. The rigid struts are sufficient to convey oscillating drivingforce applied by the motor 104 to the distal end of the drive shaft 156.Other arrangements are also contemplated. The drive shaft 156 isconfigured to carry driving power from the motor to the coupler 158.Accordingly, the drive shaft 156 is a rigidly extending structure.

The coupler 158 is disposed at the distal end of the drive shaft 156 andcouples the drive shaft 156 to the cutter inner cutting member 149. Insome embodiments, the coupler 158 is disposed within the drive shaft156. In some examples, it protrudes radially from the exterior surfaceof the inner cutting member 149 to the inner surface of the drive shaft156. Like the drive shaft 156, the coupler 158 is a rigid structureconfigured to convey the oscillating displacement from the drive shaft156 to the inner cutting member 149. It may be solid or may be formedwith windows or gaps to decrease its overall weight and decrease itsdampening effect on the oscillating motor 104. In this embodiment, thedrive shaft 156, the coupler 158, and the inner cutting member 149 areall coaxially aligned in the ophthalmic probe 100.

As the drive shaft 156 axially translates in a distal and proximaldirection, the coupler 158, fixed to the drive shaft 156, alsotranslates in an oscillating manner. Because the inner cutting member149 is fixed to the coupler 158, axial displacement or translation ofthe coupler 158 results in axial displacement or translation of theinner cutting member 149 relative to the needle 106.

The stationary aspiration tube 160 and the cutter seal assembly 162 aredisposed within the drive shaft 156. These form a portion of anaspiration pathway through the ophthalmic probe 100. For example, theaspiration pathway includes the port 146, the inner cutting member 149,the aspiration tube 160, and the aspiration port 131. In the exemplaryembodiment shown, the aspiration tube 160 and the cutter seal assembly162 are fixed in place relative to the body portion 110 of theophthalmic probe 100. As such, as the drive shaft 156, the coupler 158,and the inner cutting member 149 oscillate via the motor 104, theaspiration tube 160 and the cutter seal assembly 162 are substantiallyfixed in place.

In the embodiment shown, the aspiration tube 160 is a tube affixedcoaxially with the inner cutting member 149 and extends from the innercutting member 149 to a position proximal of the motor 104. Accordingly,in the exemplary embodiment in FIG. 2, it is also coaxial with the driveshaft 156. The aspiration tube 160 has a diameter greater than thediameter of the inner cutting member 149 so that the aspirating flow canbe more easily induced without the same levels of pressure lossencountered in the smaller diameter inner cutting member 149. Here, theaspiration tube 160 is coaxially aligned with the aspiration port 131,and the aspiration tube 160 may be connected directly to the aspirationline of the lines 16 (FIG. 1) connecting the ophthalmic probe to thebase housing 12 of the ophthalmic surgical system 10.

The cutter seal assembly 162 connects the distal portion of theaspiration tube 160 to the inner cutting member 149. In this embodiment,the cutter seal assembly 162 is fixed relative to the aspiration tube 60and, therefore, the inner cutting member 149 moves relative to thecutter seal assembly 162. The cutter seal assembly also transitions theaspiration pathway from the smaller diameter inner cutting member 149 tothe larger diameter aspiration tube 160. The cutter seal assembly 162 isattached at the distal end of the aspiration tube 160 and is configuredto house one or more seals 164 that seal around the inner cutting member149 to prevent leakage of aspiration fluid from the aspiration pathwayand prevent drawing of air into the aspiration pathway from the innerportions of the body portion 110. In the embodiment shown, the seal 164is an O-ring, although other seals may be used. In this embodiment, thecutter seal assembly 162 is sized to receive the distal end of theaspiration tube 160 therein, and may be glued, laser or spot welded, orotherwise adhered to the aspiration tube 160.

Since the cutter seal assembly 162 is fixed in place relative to theaspiration tube 160, and the aspiration tube 160 is substantially orcompletely fixed in place relative to the body portion of the ophthalmicprobe 100, the volume change within the aspiration tube 160 as a resultof the oscillating inner cutting member 149 is minimized, resulting in adecreased chance of fluid surge within the aspiration line compared tovitrectomy probes that have a coupler that moves with inner cuttingmember 149. This becomes apparent with reference to FIG. 4.

FIG. 4 shows an enlarged view of the cutter seal assembly 162 and aportion of the aspiration tube 160 and the inner cutter member 149. Ascan be seen the inner cutting member 149 has a first smaller diameter D1and the aspiration tube 160 has a second larger diameter D2. In order toreduce pressure loss occurring from long lengths of fluid pathways withminimal diameters, the aspiration pathway is designed to expand topromote more consistent and easier flow. Accordingly, the aspirationflow is configured to expand from the minimal diameter of the innercutting member 149 to the larger diameter of the aspiration tube 160.

In this example, the inner cutting member 149 is disposed at the extremedistal position during a cutting cycle. The dashed lines indicate theposition of the inner cutting member 149 at an extreme proximal positionduring a cutting cycle. The dashed lines also represent the change involume that occurs locally within the aspiration pathway as a result ofthe displaced inner cutting member 149 during a cutting cycle. As can beseen in FIG. 4, the change in volume that occurs within the aspirationpathway is limited to the volume displaced by the inner cutting member149. Because the inner cutting member has a small outer diameter (in therange of about 0.025 to 0.012 in.) and an inner diameter (in the rangeof about 0.020 to 0.010 in.), and because the cutting cycle axialdisplacement is often in the range of about 0.010-0.050 in., the totalvolume displacement is minimal. In some embodiments, the total volumedisplacement is less than about 9×10⁻⁶ in³, and in other embodiments,the total volume displacement is less than about 4×10⁻⁷ in³. Yet othervalues and ranges are contemplated.

The displacement volume in the aspiration pathway of the ophthalmicprobe 100 may be a substantially smaller displacement volume than can beachieved in conventional devices where a coupler is disposed in place ofthe cutter seal assembly. The conventional coupler fixedly connects tothe inner cutting member and therefore moves with the inner cuttingmember. As both the coupler and the inner cutting member oscillateduring a cutting cycle in the conventional device, the fluid volumedisplacement is much larger than when only the inner cutting memberoscillates. The fluid volume displacement in conventional devices may beas much as, for example only, 7-50 times larger (depending on the sizeof the inner cutting member) than the volume displacement that occurs inthe system disclosed herein. This large displacement in prior devicesmay manifest itself as pulses or fluid surges. In some instances, thismay result in a reversal of flow during vitrectomy cutting or inagitation resulting in gas coming out of solution.

In use, a surgeon sets a cutting rate at the surgical base housing 112.The fluidic pressure source and the probe driver drive the motor 104 toactuate the cutter assembly 108 at the designated cutting rate. It doesthis by driving the drive shaft 156 at the designated cutting rate. Thedrive shaft 156 is rigidly fixed to and drives the coupler 158. Thecoupler 158 is rigidly fixed to and drives the inner cutting member 149.Since the drive shaft 156 and the coupler 158 operate within air, and donot physically contact or disrupt fluid or tissue, the dampening effectis smaller than if the drive shaft 156 and the coupler 158 were to be incontact with the aspiration fluid or if maintained within a fluidchamber.

Accordingly, during a cutting cycle, when the motor drives the driveshaft and the coupler in the distal direction, the inner cutting member149 makes a cutting motion in the needle 106 by advancing across theport 146 until it is closed. As this occurs, the proximal end of theinner cutting member 149 moves distally relative to the aspiration tube160 and the cutter seal assembly 162. Because only the inner cuttingmember 149 moves distally, there is very little volume change in theaspiration pathway, and the aspiration flow is only minimally affected.

When the inner cutting member 149 reaches the distal-most position, themotor drives the cutter assembly 108 in the proximal direction. Again,it does this by moving the drive shaft 156, the coupler 158, and theinner cutting member 149 in the distal direction. This opens the port149 permitting additional fluid and tissue to enter the needle 106. Asthe inner cutting member 149 moves in the proximal direction, its volumewithin the aspiration tube 160 increases as shown in FIG. 4. Since theaspiration tube 160 and the cutter seal assembly 162 are fixed in place,only the inner cutting member 149 affects the volume within theaspiration pathway. Because only the inner cutting member 149 movesproximally, there is very little volume change in the aspirationpathway, and the aspiration flow is only minimally affected.

FIG. 5 illustrates another cross-sectional view of an ophthalmic probe300 (which in some embodiments is the probe 100). The probe 300 includesmany features similar to the probe 100 discussed herein. For the sake ofsimplicity, some reference numbers are used to designate the same orsimilar parts. For example, the ophthalmic probe 300 includes a housing102 and a cutter 105 extending from the housing 102. The probe 300 alsoincludes a motor 301 disposed within a motor chamber 303 in the housing102, and includes a cutter assembly 302. In this embodiment, the cutterassembly 302 includes the stationary aspiration tube 160, a cutter sealhousing portion 304, and the inner cutting member 149. The cutter sealhousing portion 304 is fixed in place and does not move relative to thestationary aspiration tube 160 and therefore, does not move relative tothe probe housing 102. While the stationary aspiration tube 160 is shownin the cross-sectional view of FIG. 5 as a separate component from thebody 102, other embodiments have the stationary aspiration tube 160formed as a part of the body with the stationary aspiration tube 160being an integral or monolithic portion of the body 102.

In this embodiment, the motor 301 is connected directly to the innercutting member 149 in a manner that drives the inner cutting member 149in a cutting cycle. Accordingly, only the inner cutting member 149 moveswithin the aspiration pathway, and therefore, similar to the embodimentin FIG. 2, there is very little volume change in the aspiration pathwayduring a cutting cycle. In this example, the motor 301 is disposed inthe distal portion of the probe 300. Also in this example, the motor 301is disposed distal of the proximal end of the inner cutting member 149and is configured to drive the inner cutting member 149.

The motor 301 may be similar to the motor 104 and may include a flexiblediaphragm and a rigid coupler that operates by pressure variationbetween the first and second ports 128, 130. The variation in pressureon opposing sides of the motor 301 within the motor chamber causes thediaphragm 140 to vibrate, carrying the inner cutting member 149 in aback-and-forth oscillating motion. Other arrangements are alsocontemplated.

Persons of ordinary skill in the art will appreciate that theembodiments encompassed by the present disclosure are not limited to theparticular exemplary embodiments described above. In that regard,although illustrative embodiments have been shown and described, a widerange of modification, change, and substitution is contemplated in theforegoing disclosure. It is understood that such variations may be madeto the foregoing without departing from the scope of the presentdisclosure. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the presentdisclosure.

I claim:
 1. An ophthalmic apparatus for performing an ocular surgery,comprising: an ophthalmic probe body graspable by a user; an aspirationtube disposed within the probe body and having a lumen arranged tocontact aspiration fluid flowing therethrough; a cutter extending fromthe body and comprising a first cutting member and a second cuttingmember, the first cutting member being at least partially disposedwithin and moveable relative to the second cutting member, the firstcutting member having a lumen having a first diameter, the secondcutting member having a distal end with a port formed therein forreceiving patient tissue, the first cutting member configured to beaxially displaceable within the second cutting member and within aportion of the lumen of the aspiration tube; and a motor within theprobe body configured to actuate the first cutting member relative tothe second cutting member and the lumen.
 2. The ophthalmic apparatus ofclaim 1, wherein the motor is disposed between the aspiration tube andthe second cutting member.
 3. The ophthalmic apparatus of claim 1,wherein the lumen of the aspiration tube has a diameter larger than theouter diameter of the first cutting member.
 4. The ophthalmic apparatusof claim 1, wherein the second cutting member and the aspiration tubeare statically connected to the probe body.
 5. The ophthalmic apparatusof claim 1, wherein the first cutting member, the second cutting member,and the aspiration tube form an aspiration pathway configured toaspirate tissue cut during the ocular surgery
 6. The ophthalmicapparatus of claim 1, wherein the motor is disposed in a distal portionof the ophthalmic probe body.
 7. The ophthalmic apparatus of claim 1,wherein the first cutting member is coaxial with the second cuttingmember and the lumen.
 8. The ophthalmic apparatus of claim 1, furthercomprising a cutter seal affixed to the second cutting member, thecutter seal configured to prevent fluid from passing between the firstcutting member and the second cutting member.
 9. An ophthalmic apparatusfor performing an ocular surgery, comprising: an ophthalmic probe bodygraspable by a user; a first stationary aspiration tube having a firstaspiration lumen disposed within the probe body, the first aspirationlumen arranged to contact aspiration fluid flowing therethrough; acutting assembly comprising an axially displaceable cutting memberforming a second aspiration lumen, the cutting member movably disposedwithin a portion of the first aspiration lumen, the first and secondaspiration lumens configured to aspirate fluid through the probe body;and a motor within the probe body configured to actuate the cuttingmember relative to the first aspiration lumen and the second aspirationlumen.
 10. The ophthalmic apparatus of claim 9, wherein the firststationary aspiration tube and the cutting assembly form an aspirationpathway configured to aspirate tissue cut during the ocular surgery. 11.The ophthalmic apparatus of claim 9, wherein the lumen of the aspirationtube has a diameter larger than the outer diameter of the first cuttingmember.
 12. The ophthalmic apparatus of claim 9, wherein the motor isdisposed between the first stationary aspiration tube and a secondaspiration lumen.
 13. The ophthalmic apparatus of claim 9, wherein thefirst aspiration lumen and second aspiration lumen are staticallyconnected to the probe body.
 14. The ophthalmic apparatus of claim 9,wherein the cutting member is coaxial with the first aspiration lumenand the second aspiration lumen.
 15. The ophthalmic apparatus of claim9, further comprising a cutter seal affixed to the second aspirationlumen, the cutter seal configured to prevent fluid from passing betweenthe cutting member and the second aspiration lumen.
 16. A method ofdriving a cutting assembly of an ophthalmic probe, comprising: openingan aspiration port between a first cutting member and a second cuttingmember on a distal end of the ophthalmic probe, the first cutting membermovably disposed within the second cutting member; driving, with a motordisposed in the distal region of the ophthalmic probe, the first cuttingmember relative to the second cutting member to close the aspirationport and cut tissue at a surgery site; and aspirating the cut tissuefrom the surgery site through the first cutting member, the secondcutting member, and a stationary aspiration tube disposed within theophthalmic probe, the stationary aspiration tube having a lumen.
 17. Themethod of claim 16, further comprising forming a seal between the firstcutting member and the second cutting member such that cut tissue isretained within the first cutting member, the second cutting member, andthe aspiration lumen.
 18. The method of claim 16, further comprisingplacing the first cutting member within a portion of the aspirationlumen.
 19. The method of claim 18, further comprising driving the firstcutting member such that it moves within a portion of the aspirationlumen.
 20. The method of claim 19, further comprising driving, with themotor, the first cutting member relative to the stationary aspirationtube.